Observation of electrolytic capacitor ageing behaviour for the purpose of prognostics

Abstract

Abstract-Electrolytic capacitors are an important component within power electronics systems which are known to exhibit poorer reliability compared to other components within the system. In this paper, the changes in electrical parameters (capacitance and equivalent series resistance) which occur as electrolytic capacitors age are characterised at regular intervals over the life of the capacitors. Ageing is observed under three different bias conditions: no bias; constant voltage bias and square wave excitation and at two different ambient temperatures. The data captured within this work presents the changes in capacitor properties from new, reaching to a point which the capacitor parameters have changed sufficiently, such that the capacitor can be considered to have failed. Such data will prove valuable in the development of a system designed to determine the state of health of a capacitor, or could be used to predict its remaining useful lifetime.

Using LSTM neural network to predict remaining useful life of electrolytic capacitors in dynamic operating conditions

“…For many applications, capacitor failure is considered to occur when the ESR increases by 200% of its initial value. 30,31 In Zhou et al 32 and Abdennadher et al, 33 the exponential model is used to capture the aging of capacitor at a constant temperature T as:…”

“…For many applications, capacitor failure is considered to occur when the ESR increases by 200% of its initial value. 30,31…”

Electric Stress in Power Electronics Applications

“…Because of the aforementioned adjustable parameters, up to now, the definition of robust ageing curves is a main issue because of the high variability of the coefficient characterizing the resulting curves [4], [8], [9]. Therefore, testing campaigns proved to be unfit for purpose, they simply required a too large training set to be statistically-speaking robust.…”

“…• defining a feasible and sustainable electric stress monitoring framework. In fact, the main problem in dielectric ageing monitoring is the great variability of the life behaviour depending on the operating conditions [8], [9]. This would require, in fact, large-scale validation and testing campaigns for all the different possible installations, thus viable alternative solutions have to be looked for.…”